1 ### the gnu tar specification:
2 ### http://www.gnu.org/software/tar/manual/tar.html
4 ### and the pax format spec, which tar derives from:
5 ### http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html
13 use Carp qw(carp croak);
15 use File::Spec::Unix ();
18 use Archive::Tar::File;
19 use Archive::Tar::Constant;
24 use vars qw[$DEBUG $error $VERSION $WARN $FOLLOW_SYMLINK $CHOWN $CHMOD
25 $DO_NOT_USE_PREFIX $HAS_PERLIO $HAS_IO_STRING
26 $INSECURE_EXTRACT_MODE @ISA @EXPORT
30 @EXPORT = qw[ COMPRESS_GZIP COMPRESS_BZIP ];
37 $DO_NOT_USE_PREFIX = 0;
38 $INSECURE_EXTRACT_MODE = 0;
42 $HAS_PERLIO = $Config::Config{useperlio};
44 ### try and load IO::String anyway, so you can dynamically
45 ### switch between perlio and IO::String
46 $HAS_IO_STRING = eval {
55 Archive::Tar - module for manipulations of tar archives
60 my $tar = Archive::Tar->new;
62 $tar->read('origin.tgz');
65 $tar->add_files('file/foo.pl', 'docs/README');
66 $tar->add_data('file/baz.txt', 'This is the contents now');
68 $tar->rename('oldname', 'new/file/name');
70 $tar->write('files.tar'); # plain tar
71 $tar->write('files.tgz', COMPRESS_GZIP); # gzip compressed
72 $tar->write('files.tbz', COMPRESS_BZIP); # bzip2 compressed
76 Archive::Tar provides an object oriented mechanism for handling tar
77 files. It provides class methods for quick and easy files handling
78 while also allowing for the creation of tar file objects for custom
79 manipulation. If you have the IO::Zlib module installed,
80 Archive::Tar will also support compressed or gzipped tar files.
82 An object of class Archive::Tar represents a .tar(.gz) archive full
87 =head2 Archive::Tar->new( [$file, $compressed] )
89 Returns a new Tar object. If given any arguments, C<new()> calls the
90 C<read()> method automatically, passing on the arguments provided to
93 If C<new()> is invoked with arguments and the C<read()> method fails
94 for any reason, C<new()> returns undef.
103 ### install get/set accessors for this object.
104 for my $key ( keys %$tmpl ) {
106 *{__PACKAGE__."::$key"} = sub {
108 $self->{$key} = $_[0] if @_;
109 return $self->{$key};
115 $class = ref $class if ref $class;
117 ### copying $tmpl here since a shallow copy makes it use the
118 ### same aref, causing for files to remain in memory always.
119 my $obj = bless { _data => [ ], _file => 'Unknown' }, $class;
122 unless ( $obj->read( @_ ) ) {
123 $obj->_error(qq[No data could be read from file]);
131 =head2 $tar->read ( $filename|$handle, [$compressed, {opt => 'val'}] )
133 Read the given tar file into memory.
134 The first argument can either be the name of a file or a reference to
135 an already open filehandle (or an IO::Zlib object if it's compressed)
137 The C<read> will I<replace> any previous content in C<$tar>!
139 The second argument may be considered optional, but remains for
140 backwards compatibility. Archive::Tar now looks at the file
141 magic to determine what class should be used to open the file
142 and will transparently Do The Right Thing.
144 Archive::Tar will warn if you try to pass a bzip2 compressed file and the
145 IO::Zlib / IO::Uncompress::Bunzip2 modules are not available and simply return.
147 Note that you can currently B<not> pass a C<gzip> compressed
148 filehandle, which is not opened with C<IO::Zlib>, a C<bzip2> compressed
149 filehandle, which is not opened with C<IO::Uncompress::Bunzip2>, nor a string
150 containing the full archive information (either compressed or
151 uncompressed). These are worth while features, but not currently
152 implemented. See the C<TODO> section.
154 The third argument can be a hash reference with options. Note that
155 all options are case-sensitive.
161 Do not read more than C<limit> files. This is useful if you have
162 very big archives, and are only interested in the first few files.
166 Can be set to a regular expression. Only files with names that match
167 the expression will be read.
171 If set to true, immediately extract entries when reading them. This
172 gives you the same memory break as the C<extract_archive> function.
173 Note however that entries will not be read into memory, but written
174 straight to disk. This means no C<Archive::Tar::File> objects are
175 created for you to inspect.
179 All files are stored internally as C<Archive::Tar::File> objects.
180 Please consult the L<Archive::Tar::File> documentation for details.
182 Returns the number of files read in scalar context, and a list of
183 C<Archive::Tar::File> objects in list context.
190 my $gzip = shift || 0;
191 my $opts = shift || {};
193 unless( defined $file ) {
194 $self->_error( qq[No file to read from!] );
197 $self->_file( $file );
200 my $handle = $self->_get_handle($file, $gzip, READ_ONLY->( ZLIB ) )
203 my $data = $self->_read_tar( $handle, $opts ) or return;
205 $self->_data( $data );
207 return wantarray ? @$data : scalar @$data;
212 my $file = shift; return unless defined $file;
213 return $file if ref $file;
214 my $compress = shift || 0;
215 my $mode = shift || READ_ONLY->( ZLIB ); # default to read only
218 ### get a FH opened to the right class, so we can use it transparently
219 ### throughout the program
221 { ### reading magic only makes sense if we're opening a file for
222 ### reading. otherwise, just use what the user requested.
224 if( MODE_READ->($mode) ) {
225 open my $tmp, $file or do {
226 $self->_error( qq[Could not open '$file' for reading: $!] );
230 ### read the first 4 bites of the file to figure out which class to
231 ### use to open the file.
232 sysread( $tmp, $magic, 4 );
237 ### if you asked specifically for bzip compression, or if we're in
238 ### read mode and the magic numbers add up, use bzip
240 ($compress eq COMPRESS_BZIP) or
241 ( MODE_READ->($mode) and $magic =~ BZIP_MAGIC_NUM )
245 ### different reader/writer modules, different error vars... sigh
246 if( MODE_READ->($mode) ) {
247 $fh = IO::Uncompress::Bunzip2->new( $file ) or do {
248 $self->_error( qq[Could not read '$file': ] .
249 $IO::Uncompress::Bunzip2::Bunzip2Error
255 $fh = IO::Compress::Bzip2->new( $file ) or do {
256 $self->_error( qq[Could not write to '$file': ] .
257 $IO::Compress::Bzip2::Bzip2Error
264 ### if you asked for compression, if you wanted to read or the gzip
265 ### magic number is present (redundant with read)
267 $compress or MODE_READ->($mode) or $magic =~ GZIP_MAGIC_NUM
272 unless( $fh->open( $file, $mode ) ) {
273 $self->_error(qq[Could not create filehandle for '$file': $!]);
281 unless( $fh->open( $file, $mode ) ) {
282 $self->_error(qq[Could not create filehandle for '$file': $!]);
286 ### enable bin mode on tar archives
297 my $handle = shift or return;
298 my $opts = shift || {};
300 my $count = $opts->{limit} || 0;
301 my $filter = $opts->{filter};
302 my $extract = $opts->{extract} || 0;
304 ### set a cap on the amount of files to extract ###
306 $limit = 1 if $count > 0;
311 my $real_name; # to set the name of a file when
312 # we're encountering @longlink
316 while( $handle->read( $chunk, HEAD ) ) {
317 ### IO::Zlib doesn't support this yet
318 my $offset = eval { tell $handle } || 'unknown';
321 my $gzip = GZIP_MAGIC_NUM;
322 if( $chunk =~ /$gzip/ ) {
323 $self->_error( qq[Cannot read compressed format in tar-mode] );
328 ### if we can't read in all bytes... ###
329 last if length $chunk != HEAD;
331 ### Apparently this should really be two blocks of 512 zeroes,
332 ### but GNU tar sometimes gets it wrong. See comment in the
333 ### source code (tar.c) to GNU cpio.
334 next if $chunk eq TAR_END;
336 ### according to the posix spec, the last 12 bytes of the header are
337 ### null bytes, to pad it to a 512 byte block. That means if these
338 ### bytes are NOT null bytes, it's a corrrupt header. See:
339 ### www.koders.com/c/fidCE473AD3D9F835D690259D60AD5654591D91D5BA.aspx
341 { my $nulls = join '', "\0" x 12;
342 unless( $nulls eq substr( $chunk, 500, 12 ) ) {
343 $self->_error( qq[Invalid header block at offset $offset] );
348 ### pass the realname, so we can set it 'proper' right away
349 ### some of the heuristics are done on the name, so important
352 { my %extra_args = ();
353 $extra_args{'name'} = $$real_name if defined $real_name;
355 unless( $entry = Archive::Tar::File->new( chunk => $chunk,
358 $self->_error( qq[Couldn't read chunk at offset $offset] );
364 ### http://www.gnu.org/manual/tar/html_node/tar_139.html
365 next if $entry->is_label;
367 if( length $entry->type and ($entry->is_file || $entry->is_longlink) ) {
369 if ( $entry->is_file && !$entry->validate ) {
370 ### sometimes the chunk is rather fux0r3d and a whole 512
371 ### bytes ends up in the ->name area.
372 ### clean it up, if need be
373 my $name = $entry->name;
374 $name = substr($name, 0, 100) if length $name > 100;
377 $self->_error( $name . qq[: checksum error] );
381 my $block = BLOCK_SIZE->( $entry->size );
383 $data = $entry->get_content_by_ref;
385 ### just read everything into memory
386 ### can't do lazy loading since IO::Zlib doesn't support 'seek'
387 ### this is because Compress::Zlib doesn't support it =/
388 ### this reads in the whole data in one read() call.
389 if( $handle->read( $$data, $block ) < $block ) {
390 $self->_error( qq[Read error on tarfile (missing data) '].
391 $entry->full_path ."' at offset $offset" );
395 ### throw away trailing garbage ###
396 substr ($$data, $entry->size) = "" if defined $$data;
398 ### part II of the @LongLink munging -- need to do /after/
399 ### the checksum check.
400 if( $entry->is_longlink ) {
401 ### weird thing in tarfiles -- if the file is actually a
402 ### @LongLink, the data part seems to have a trailing ^@
403 ### (unprintable) char. to display, pipe output through less.
404 ### but that doesn't *always* happen.. so check if the last
405 ### character is a control character, and if so remove it
406 ### at any rate, we better remove that character here, or tests
407 ### like 'eq' and hashlook ups based on names will SO not work
408 ### remove it by calculating the proper size, and then
409 ### tossing out everything that's longer than that size.
411 ### count number of nulls
412 my $nulls = $$data =~ tr/\0/\0/;
414 ### cut data + size by that many bytes
415 $entry->size( $entry->size - $nulls );
416 substr ($$data, $entry->size) = "";
420 ### clean up of the entries.. posix tar /apparently/ has some
421 ### weird 'feature' that allows for filenames > 255 characters
422 ### they'll put a header in with as name '././@LongLink' and the
423 ### contents will be the name of the /next/ file in the archive
424 ### pretty crappy and kludgy if you ask me
426 ### set the name for the next entry if this is a @LongLink;
427 ### this is one ugly hack =/ but needed for direct extraction
428 if( $entry->is_longlink ) {
431 } elsif ( defined $real_name ) {
432 $entry->name( $$real_name );
437 ### skip this entry if we're filtering
438 if ($filter && $entry->name !~ $filter) {
441 ### skip this entry if it's a pax header. This is a special file added
442 ### by, among others, git-generated tarballs. It holds comments and is
443 ### not meant for extracting. See #38932: pax_global_header extracted
444 } elsif ( $entry->name eq PAX_HEADER ) {
448 $self->_extract_file( $entry ) if $extract
449 && !$entry->is_longlink
450 && !$entry->is_unknown
451 && !$entry->is_label;
453 ### Guard against tarfiles with garbage at the end
454 last LOOP if $entry->name eq '';
456 ### push only the name on the rv if we're extracting
457 ### -- for extract_archive
458 push @$tarfile, ($extract ? $entry->name : $entry);
461 $count-- unless $entry->is_longlink || $entry->is_dir;
462 last LOOP unless $count;
471 =head2 $tar->contains_file( $filename )
473 Check if the archive contains a certain file.
474 It will return true if the file is in the archive, false otherwise.
476 Note however, that this function does an exact match using C<eq>
477 on the full path. So it cannot compensate for case-insensitive file-
478 systems or compare 2 paths to see if they would point to the same
487 return unless defined $full;
489 ### don't warn if the entry isn't there.. that's what this function
490 ### is for after all.
492 return 1 if $self->_find_entry($full);
496 =head2 $tar->extract( [@filenames] )
498 Write files whose names are equivalent to any of the names in
499 C<@filenames> to disk, creating subdirectories as necessary. This
500 might not work too well under VMS.
501 Under MacPerl, the file's modification time will be converted to the
502 MacOS zero of time, and appropriate conversions will be done to the
503 path. However, the length of each element of the path is not
504 inspected to see whether it's longer than MacOS currently allows (32
507 If C<extract> is called without a list of file names, the entire
508 contents of the archive are extracted.
510 Returns a list of filenames extracted.
519 # use the speed optimization for all extracted files
520 local($self->{cwd}) = cwd() unless $self->{cwd};
522 ### you requested the extraction of only certian files
524 for my $file ( @args ) {
526 ### it's already an object?
527 if( UNIVERSAL::isa( $file, 'Archive::Tar::File' ) ) {
535 for my $entry ( @{$self->_data} ) {
536 next unless $file eq $entry->full_path;
538 ### we found the file you're looking for
544 return $self->_error(
545 qq[Could not find '$file' in archive] );
550 ### just grab all the file items
552 @files = $self->get_files;
555 ### nothing found? that's an error
556 unless( scalar @files ) {
557 $self->_error( qq[No files found for ] . $self->_file );
562 for my $entry ( @files ) {
563 unless( $self->_extract_file( $entry ) ) {
564 $self->_error(q[Could not extract ']. $entry->full_path .q['] );
572 =head2 $tar->extract_file( $file, [$extract_path] )
574 Write an entry, whose name is equivalent to the file name provided to
575 disk. Optionally takes a second parameter, which is the full native
576 path (including filename) the entry will be written to.
580 $tar->extract_file( 'name/in/archive', 'name/i/want/to/give/it' );
582 $tar->extract_file( $at_file_object, 'name/i/want/to/give/it' );
584 Returns true on success, false on failure.
590 my $file = shift; return unless defined $file;
593 my $entry = $self->_find_entry( $file )
594 or $self->_error( qq[Could not find an entry for '$file'] ), return;
596 return $self->_extract_file( $entry, $alt );
601 my $entry = shift or return;
604 ### you wanted an alternate extraction location ###
605 my $name = defined $alt ? $alt : $entry->full_path;
607 ### splitpath takes a bool at the end to indicate
608 ### that it's splitting a dir
609 my ($vol,$dirs,$file);
610 if ( defined $alt ) { # It's a local-OS path
611 ($vol,$dirs,$file) = File::Spec->splitpath( $alt,
614 ($vol,$dirs,$file) = File::Spec::Unix->splitpath( $name,
619 ### is $name an absolute path? ###
620 if( $vol || File::Spec->file_name_is_absolute( $dirs ) ) {
622 ### absolute names are not allowed to be in tarballs under
623 ### strict mode, so only allow it if a user tells us to do it
624 if( not defined $alt and not $INSECURE_EXTRACT_MODE ) {
626 q[Entry ']. $entry->full_path .q[' is an absolute path. ].
627 q[Not extracting absolute paths under SECURE EXTRACT MODE]
632 ### user asked us to, it's fine.
633 $dir = File::Spec->catpath( $vol, $dirs, "" );
635 ### it's a relative path ###
637 my $cwd = (ref $self and defined $self->{cwd})
641 my @dirs = defined $alt
642 ? File::Spec->splitdir( $dirs ) # It's a local-OS path
643 : File::Spec::Unix->splitdir( $dirs ); # it's UNIX-style, likely
644 # straight from the tarball
646 if( not defined $alt and
647 not $INSECURE_EXTRACT_MODE
650 ### paths that leave the current directory are not allowed under
651 ### strict mode, so only allow it if a user tells us to do this.
652 if( grep { $_ eq '..' } @dirs ) {
655 q[Entry ']. $entry->full_path .q[' is attempting to leave ].
656 q[the current working directory. Not extracting under ].
657 q[SECURE EXTRACT MODE]
662 ### the archive may be asking us to extract into a symlink. This
663 ### is not sane and a possible security issue, as outlined here:
664 ### https://rt.cpan.org/Ticket/Display.html?id=30380
665 ### https://bugzilla.redhat.com/show_bug.cgi?id=295021
666 ### https://issues.rpath.com/browse/RPL-1716
667 my $full_path = $cwd;
668 for my $d ( @dirs ) {
669 $full_path = File::Spec->catdir( $full_path, $d );
671 ### we've already checked this one, and it's safe. Move on.
672 next if ref $self and $self->{_link_cache}->{$full_path};
674 if( -l $full_path ) {
675 my $to = readlink $full_path;
676 my $diag = "symlinked directory ($full_path => $to)";
679 q[Entry ']. $entry->full_path .q[' is attempting to ].
680 qq[extract to a $diag. This is considered a security ].
681 q[vulnerability and not allowed under SECURE EXTRACT ].
687 ### XXX keep a cache if possible, so the stats become cheaper:
688 $self->{_link_cache}->{$full_path} = 1 if ref $self;
692 ### '.' is the directory delimiter on VMS, which has to be escaped
693 ### or changed to '_' on vms. vmsify is used, because older versions
694 ### of vmspath do not handle this properly.
695 ### Must not add a '/' to an empty directory though.
696 map { length() ? VMS::Filespec::vmsify($_.'/') : $_ } @dirs if ON_VMS;
698 my ($cwd_vol,$cwd_dir,$cwd_file)
699 = File::Spec->splitpath( $cwd );
700 my @cwd = File::Spec->splitdir( $cwd_dir );
701 push @cwd, $cwd_file if length $cwd_file;
703 ### We need to pass '' as the last elemant to catpath. Craig Berry
704 ### explains why (msgid <p0624083dc311ae541393@[172.16.52.1]>):
705 ### The root problem is that splitpath on UNIX always returns the
706 ### final path element as a file even if it is a directory, and of
707 ### course there is no way it can know the difference without checking
708 ### against the filesystem, which it is documented as not doing. When
709 ### you turn around and call catpath, on VMS you have to know which bits
710 ### are directory bits and which bits are file bits. In this case we
711 ### know the result should be a directory. I had thought you could omit
712 ### the file argument to catpath in such a case, but apparently on UNIX
714 $dir = File::Spec->catpath(
715 $cwd_vol, File::Spec->catdir( @cwd, @dirs ), ''
718 ### catdir() returns undef if the path is longer than 255 chars on
719 ### older VMS systems.
720 unless ( defined $dir ) {
721 $^W && $self->_error( qq[Could not compose a path for '$dirs'\n] );
727 if( -e $dir && !-d _ ) {
728 $^W && $self->_error( qq['$dir' exists, but it's not a directory!\n] );
733 eval { File::Path::mkpath( $dir, 0, 0777 ) };
735 my $fp = $entry->full_path;
736 $self->_error(qq[Could not create directory '$dir' for '$fp': $@]);
740 ### XXX chown here? that might not be the same as in the archive
741 ### as we're only chown'ing to the owner of the file we're extracting
742 ### not to the owner of the directory itself, which may or may not
743 ### be another entry in the archive
744 ### Answer: no, gnu tar doesn't do it either, it'd be the wrong
746 #if( $CHOWN && CAN_CHOWN ) {
747 # chown $entry->uid, $entry->gid, $dir or
748 # $self->_error( qq[Could not set uid/gid on '$dir'] );
752 ### we're done if we just needed to create a dir ###
753 return 1 if $entry->is_dir;
755 my $full = File::Spec->catfile( $dir, $file );
757 if( $entry->is_unknown ) {
758 $self->_error( qq[Unknown file type for file '$full'] );
762 if( length $entry->type && $entry->is_file ) {
763 my $fh = IO::File->new;
764 $fh->open( '>' . $full ) or (
765 $self->_error( qq[Could not open file '$full': $!] ),
771 syswrite $fh, $entry->data or (
772 $self->_error( qq[Could not write data to '$full'] ),
778 $self->_error( qq[Could not close file '$full'] ),
783 $self->_make_special_file( $entry, $full ) or return;
786 ### only update the timestamp if it's not a symlink; that will change the
787 ### timestamp of the original. This addresses bug #33669: Could not update
788 ### timestamp warning on symlinks
790 utime time, $entry->mtime - TIME_OFFSET, $full or
791 $self->_error( qq[Could not update timestamp] );
794 if( $CHOWN && CAN_CHOWN->() ) {
795 chown $entry->uid, $entry->gid, $full or
796 $self->_error( qq[Could not set uid/gid on '$full'] );
799 ### only chmod if we're allowed to, but never chmod symlinks, since they'll
800 ### change the perms on the file they're linking too...
801 if( $CHMOD and not -l $full ) {
802 chmod $entry->mode, $full or
803 $self->_error( qq[Could not chown '$full' to ] . $entry->mode );
809 sub _make_special_file {
811 my $entry = shift or return;
812 my $file = shift; return unless defined $file;
816 if( $entry->is_symlink ) {
819 symlink( $entry->linkname, $file ) or $fail++;
822 $self->_extract_special_file_as_plain_file( $entry, $file )
826 $err = qq[Making symbolic link '$file' to '] .
827 $entry->linkname .q[' failed] if $fail;
829 } elsif ( $entry->is_hardlink ) {
832 link( $entry->linkname, $file ) or $fail++;
835 $self->_extract_special_file_as_plain_file( $entry, $file )
839 $err = qq[Making hard link from '] . $entry->linkname .
840 qq[' to '$file' failed] if $fail;
842 } elsif ( $entry->is_fifo ) {
843 ON_UNIX && !system('mknod', $file, 'p') or
844 $err = qq[Making fifo ']. $entry->name .qq[' failed];
846 } elsif ( $entry->is_blockdev or $entry->is_chardev ) {
847 my $mode = $entry->is_blockdev ? 'b' : 'c';
849 ON_UNIX && !system('mknod', $file, $mode,
850 $entry->devmajor, $entry->devminor) or
851 $err = qq[Making block device ']. $entry->name .qq[' (maj=] .
852 $entry->devmajor . qq[ min=] . $entry->devminor .
855 } elsif ( $entry->is_socket ) {
856 ### the original doesn't do anything special for sockets.... ###
860 return $err ? $self->_error( $err ) : 1;
863 ### don't know how to make symlinks, let's just extract the file as
865 sub _extract_special_file_as_plain_file {
867 my $entry = shift or return;
868 my $file = shift; return unless defined $file;
872 my $orig = $self->_find_entry( $entry->linkname );
875 $err = qq[Could not find file '] . $entry->linkname .
880 ### clone the entry, make it appear as a normal file ###
881 my $clone = $entry->clone;
882 $clone->_downgrade_to_plainfile;
883 $self->_extract_file( $clone, $file ) or last TRY;
888 return $self->_error($err);
891 =head2 $tar->list_files( [\@properties] )
893 Returns a list of the names of all the files in the archive.
895 If C<list_files()> is passed an array reference as its first argument
896 it returns a list of hash references containing the requested
897 properties of each file. The following list of properties is
898 supported: name, size, mtime (last modified date), mode, uid, gid,
899 linkname, uname, gname, devmajor, devminor, prefix.
901 Passing an array reference containing only one element, 'name', is
902 special cased to return a list of names rather than a list of hash
903 references, making it equivalent to calling C<list_files> without
910 my $aref = shift || [ ];
912 unless( $self->_data ) {
913 $self->read() or return;
916 if( @$aref == 0 or ( @$aref == 1 and $aref->[0] eq 'name' ) ) {
917 return map { $_->full_path } @{$self->_data};
921 #for my $obj ( @{$self->_data} ) {
922 # push @rv, { map { $_ => $obj->$_() } @$aref };
926 ### this does the same as the above.. just needs a +{ }
927 ### to make sure perl doesn't confuse it for a block
928 return map { my $o=$_;
929 +{ map { $_ => $o->$_() } @$aref }
938 unless( defined $file ) {
939 $self->_error( qq[No file specified] );
943 ### it's an object already
944 return $file if UNIVERSAL::isa( $file, 'Archive::Tar::File' );
946 for my $entry ( @{$self->_data} ) {
947 my $path = $entry->full_path;
948 return $entry if $path eq $file;
951 $self->_error( qq[No such file in archive: '$file'] );
955 =head2 $tar->get_files( [@filenames] )
957 Returns the C<Archive::Tar::File> objects matching the filenames
958 provided. If no filename list was passed, all C<Archive::Tar::File>
959 objects in the current Tar object are returned.
961 Please refer to the C<Archive::Tar::File> documentation on how to
962 handle these objects.
969 return @{ $self->_data } unless @_;
972 for my $file ( @_ ) {
973 push @list, grep { defined } $self->_find_entry( $file );
979 =head2 $tar->get_content( $file )
981 Return the content of the named file.
987 my $entry = $self->_find_entry( shift ) or return;
992 =head2 $tar->replace_content( $file, $content )
994 Make the string $content be the content for the file named $file.
998 sub replace_content {
1000 my $entry = $self->_find_entry( shift ) or return;
1002 return $entry->replace_content( shift );
1005 =head2 $tar->rename( $file, $new_name )
1007 Rename the file of the in-memory archive to $new_name.
1009 Note that you must specify a Unix path for $new_name, since per tar
1010 standard, all files in the archive must be Unix paths.
1012 Returns true on success and false on failure.
1018 my $file = shift; return unless defined $file;
1019 my $new = shift; return unless defined $new;
1021 my $entry = $self->_find_entry( $file ) or return;
1023 return $entry->rename( $new );
1026 =head2 $tar->remove (@filenamelist)
1028 Removes any entries with names matching any of the given filenames
1029 from the in-memory archive. Returns a list of C<Archive::Tar::File>
1030 objects that remain.
1038 my %seen = map { $_->full_path => $_ } @{$self->_data};
1039 delete $seen{ $_ } for @list;
1041 $self->_data( [values %seen] );
1043 return values %seen;
1048 C<clear> clears the current in-memory archive. This effectively gives
1049 you a 'blank' object, ready to be filled again. Note that C<clear>
1050 only has effect on the object, not the underlying tarfile.
1055 my $self = shift or return;
1064 =head2 $tar->write ( [$file, $compressed, $prefix] )
1066 Write the in-memory archive to disk. The first argument can either
1067 be the name of a file or a reference to an already open filehandle (a
1070 The second argument is used to indicate compression. You can either
1071 compress using C<gzip> or C<bzip2>. If you pass a digit, it's assumed
1072 to be the C<gzip> compression level (between 1 and 9), but the use of
1073 constants is prefered:
1075 # write a gzip compressed file
1076 $tar->write( 'out.tgz', COMPRESS_GZIP );
1078 # write a bzip compressed file
1079 $tar->write( 'out.tbz', COMPRESS_BZIP );
1081 Note that when you pass in a filehandle, the compression argument
1082 is ignored, as all files are printed verbatim to your filehandle.
1083 If you wish to enable compression with filehandles, use an
1084 C<IO::Zlib> or C<IO::Compress::Bzip2> filehandle instead.
1086 The third argument is an optional prefix. All files will be tucked
1087 away in the directory you specify as prefix. So if you have files
1088 'a' and 'b' in your archive, and you specify 'foo' as prefix, they
1089 will be written to the archive as 'foo/a' and 'foo/b'.
1091 If no arguments are given, C<write> returns the entire formatted
1092 archive as a string, which could be useful if you'd like to stuff the
1093 archive into a socket or a pipe to gzip or something.
1100 my $file = shift; $file = '' unless defined $file;
1101 my $gzip = shift || 0;
1102 my $ext_prefix = shift; $ext_prefix = '' unless defined $ext_prefix;
1105 ### only need a handle if we have a file to print to ###
1106 my $handle = length($file)
1107 ? ( $self->_get_handle($file, $gzip, WRITE_ONLY->($gzip) )
1109 : $HAS_PERLIO ? do { open my $h, '>', \$dummy; $h }
1110 : $HAS_IO_STRING ? IO::String->new
1111 : __PACKAGE__->no_string_support();
1113 ### Addresses: #41798: Nonempty $\ when writing a TAR file produces a
1114 ### corrupt TAR file. Must clear out $\ to make sure no garbage is
1115 ### printed to the archive
1118 for my $entry ( @{$self->_data} ) {
1119 ### entries to be written to the tarfile ###
1122 ### only now will we change the object to reflect the current state
1123 ### of the name and prefix fields -- this needs to be limited to
1125 my $clone = $entry->clone;
1128 ### so, if you don't want use to use the prefix, we'll stuff
1129 ### everything in the name field instead
1130 if( $DO_NOT_USE_PREFIX ) {
1132 ### you might have an extended prefix, if so, set it in the clone
1133 ### XXX is ::Unix right?
1134 $clone->name( length $ext_prefix
1135 ? File::Spec::Unix->catdir( $ext_prefix,
1137 : $clone->full_path );
1138 $clone->prefix( '' );
1140 ### otherwise, we'll have to set it properly -- prefix part in the
1141 ### prefix and name part in the name field.
1144 ### split them here, not before!
1145 my ($prefix,$name) = $clone->_prefix_and_file( $clone->full_path );
1147 ### you might have an extended prefix, if so, set it in the clone
1148 ### XXX is ::Unix right?
1149 $prefix = File::Spec::Unix->catdir( $ext_prefix, $prefix )
1150 if length $ext_prefix;
1152 $clone->prefix( $prefix );
1153 $clone->name( $name );
1156 ### names are too long, and will get truncated if we don't add a
1157 ### '@LongLink' file...
1158 my $make_longlink = ( length($clone->name) > NAME_LENGTH or
1159 length($clone->prefix) > PREFIX_LENGTH
1162 ### perhaps we need to make a longlink file?
1163 if( $make_longlink ) {
1164 my $longlink = Archive::Tar::File->new(
1165 data => LONGLINK_NAME,
1167 { type => LONGLINK }
1170 unless( $longlink ) {
1171 $self->_error( qq[Could not create 'LongLink' entry for ] .
1172 qq[oversize file '] . $clone->full_path ."'" );
1176 push @write_me, $longlink;
1179 push @write_me, $clone;
1181 ### write the one, optionally 2 a::t::file objects to the handle
1182 for my $clone (@write_me) {
1184 ### if the file is a symlink, there are 2 options:
1185 ### either we leave the symlink intact, but then we don't write any
1186 ### data OR we follow the symlink, which means we actually make a
1187 ### copy. if we do the latter, we have to change the TYPE of the
1189 my $link_ok = $clone->is_symlink && $Archive::Tar::FOLLOW_SYMLINK;
1190 my $data_ok = !$clone->is_symlink && $clone->has_content;
1192 ### downgrade to a 'normal' file if it's a symlink we're going to
1193 ### treat as a regular file
1194 $clone->_downgrade_to_plainfile if $link_ok;
1196 ### get the header for this block
1197 my $header = $self->_format_tar_entry( $clone );
1199 $self->_error(q[Could not format header for: ] .
1200 $clone->full_path );
1204 unless( print $handle $header ) {
1205 $self->_error(q[Could not write header for: ] .
1210 if( $link_ok or $data_ok ) {
1211 unless( print $handle $clone->data ) {
1212 $self->_error(q[Could not write data for: ] .
1217 ### pad the end of the clone if required ###
1218 print $handle TAR_PAD->( $clone->size ) if $clone->size % BLOCK
1221 } ### done writing these entries
1224 ### write the end markers ###
1225 print $handle TAR_END x 2 or
1226 return $self->_error( qq[Could not write tar end markers] );
1228 ### did you want it written to a file, or returned as a string? ###
1229 my $rv = length($file) ? 1
1230 : $HAS_PERLIO ? $dummy
1231 : do { seek $handle, 0, 0; local $/; <$handle> };
1233 ### make sure to close the handle;
1239 sub _format_tar_entry {
1241 my $entry = shift or return;
1242 my $ext_prefix = shift; $ext_prefix = '' unless defined $ext_prefix;
1243 my $no_prefix = shift || 0;
1245 my $file = $entry->name;
1246 my $prefix = $entry->prefix; $prefix = '' unless defined $prefix;
1248 ### remove the prefix from the file name
1249 ### not sure if this is still neeeded --kane
1250 ### no it's not -- Archive::Tar::File->_new_from_file will take care of
1251 ### this for us. Even worse, this would break if we tried to add a file
1253 #if( length $prefix ) {
1254 # $file =~ s/^$match//;
1257 $prefix = File::Spec::Unix->catdir($ext_prefix, $prefix)
1258 if length $ext_prefix;
1260 ### not sure why this is... ###
1261 my $l = PREFIX_LENGTH; # is ambiguous otherwise...
1262 substr ($prefix, 0, -$l) = "" if length $prefix >= PREFIX_LENGTH;
1264 my $f1 = "%06o"; my $f2 = "%11o";
1266 ### this might be optimizable with a 'changed' flag in the file objects ###
1271 (map { sprintf( $f1, $entry->$_() ) } qw[mode uid gid]),
1272 (map { sprintf( $f2, $entry->$_() ) } qw[size mtime]),
1274 "", # checksum field - space padded a bit down
1276 (map { $entry->$_() } qw[type linkname magic]),
1278 $entry->version || TAR_VERSION,
1280 (map { $entry->$_() } qw[uname gname]),
1281 (map { sprintf( $f1, $entry->$_() ) } qw[devmajor devminor]),
1283 ($no_prefix ? '' : $prefix)
1286 ### add the checksum ###
1287 substr($tar,148,7) = sprintf("%6o\0", unpack("%16C*",$tar));
1292 =head2 $tar->add_files( @filenamelist )
1294 Takes a list of filenames and adds them to the in-memory archive.
1296 The path to the file is automatically converted to a Unix like
1297 equivalent for use in the archive, and, if on MacOS, the file's
1298 modification time is converted from the MacOS epoch to the Unix epoch.
1299 So tar archives created on MacOS with B<Archive::Tar> can be read
1300 both with I<tar> on Unix and applications like I<suntar> or
1301 I<Stuffit Expander> on MacOS.
1303 Be aware that the file's type/creator and resource fork will be lost,
1304 which is usually what you want in cross-platform archives.
1306 Instead of a filename, you can also pass it an existing C<Archive::Tar::File>
1307 object from, for example, another archive. The object will be clone, and
1308 effectively be a copy of the original, not an alias.
1310 Returns a list of C<Archive::Tar::File> objects that were just added.
1316 my @files = @_ or return;
1319 for my $file ( @files ) {
1321 ### you passed an Archive::Tar::File object
1322 ### clone it so we don't accidentally have a reference to
1323 ### an object from another archive
1324 if( UNIVERSAL::isa( $file,'Archive::Tar::File' ) ) {
1325 push @rv, $file->clone;
1329 unless( -e $file || -l $file ) {
1330 $self->_error( qq[No such file: '$file'] );
1334 my $obj = Archive::Tar::File->new( file => $file );
1336 $self->_error( qq[Unable to add file: '$file'] );
1343 push @{$self->{_data}}, @rv;
1348 =head2 $tar->add_data ( $filename, $data, [$opthashref] )
1350 Takes a filename, a scalar full of data and optionally a reference to
1351 a hash with specific options.
1353 Will add a file to the in-memory archive, with name C<$filename> and
1354 content C<$data>. Specific properties can be set using C<$opthashref>.
1355 The following list of properties is supported: name, size, mtime
1356 (last modified date), mode, uid, gid, linkname, uname, gname,
1357 devmajor, devminor, prefix, type. (On MacOS, the file's path and
1358 modification times are converted to Unix equivalents.)
1360 Valid values for the file type are the following constants defined in
1361 Archive::Tar::Constants:
1373 Hard and symbolic ("soft") links; linkname should specify target.
1379 Character and block devices. devmajor and devminor should specify the major
1380 and minor device numbers.
1396 Returns the C<Archive::Tar::File> object that was just added, or
1397 C<undef> on failure.
1403 my ($file, $data, $opt) = @_;
1405 my $obj = Archive::Tar::File->new( data => $file, $data, $opt );
1407 $self->_error( qq[Unable to add file: '$file'] );
1411 push @{$self->{_data}}, $obj;
1416 =head2 $tar->error( [$BOOL] )
1418 Returns the current errorstring (usually, the last error reported).
1419 If a true value was specified, it will give the C<Carp::longmess>
1420 equivalent of the error, in effect giving you a stacktrace.
1422 For backwards compatibility, this error is also available as
1423 C<$Archive::Tar::error> although it is much recommended you use the
1424 method call instead.
1434 my $msg = $error = shift;
1435 $longmess = Carp::longmess($error);
1437 ### set Archive::Tar::WARN to 0 to disable printing
1440 carp $DEBUG ? $longmess : $msg;
1448 return shift() ? $longmess : $error;
1452 =head2 $tar->setcwd( $cwd );
1454 C<Archive::Tar> needs to know the current directory, and it will run
1455 C<Cwd::cwd()> I<every> time it extracts a I<relative> entry from the
1456 tarfile and saves it in the file system. (As of version 1.30, however,
1457 C<Archive::Tar> will use the speed optimization described below
1458 automatically, so it's only relevant if you're using C<extract_file()>).
1460 Since C<Archive::Tar> doesn't change the current directory internally
1461 while it is extracting the items in a tarball, all calls to C<Cwd::cwd()>
1462 can be avoided if we can guarantee that the current directory doesn't
1463 get changed externally.
1465 To use this performance boost, set the current directory via
1468 $tar->setcwd( cwd() );
1470 once before calling a function like C<extract_file> and
1471 C<Archive::Tar> will use the current directory setting from then on
1472 and won't call C<Cwd::cwd()> internally.
1474 To switch back to the default behaviour, use
1476 $tar->setcwd( undef );
1478 and C<Archive::Tar> will call C<Cwd::cwd()> internally again.
1480 If you're using C<Archive::Tar>'s C<exract()> method, C<setcwd()> will
1489 $self->{cwd} = $cwd;
1492 =head1 Class Methods
1494 =head2 Archive::Tar->create_archive($file, $compressed, @filelist)
1496 Creates a tar file from the list of files provided. The first
1497 argument can either be the name of the tar file to create or a
1498 reference to an open file handle (e.g. a GLOB reference).
1500 The second argument is used to indicate compression. You can either
1501 compress using C<gzip> or C<bzip2>. If you pass a digit, it's assumed
1502 to be the C<gzip> compression level (between 1 and 9), but the use of
1503 constants is prefered:
1505 # write a gzip compressed file
1506 Archive::Tar->create_archive( 'out.tgz', COMPRESS_GZIP, @filelist );
1508 # write a bzip compressed file
1509 Archive::Tar->create_archive( 'out.tbz', COMPRESS_BZIP, @filelist );
1511 Note that when you pass in a filehandle, the compression argument
1512 is ignored, as all files are printed verbatim to your filehandle.
1513 If you wish to enable compression with filehandles, use an
1514 C<IO::Zlib> or C<IO::Compress::Bzip2> filehandle instead.
1516 The remaining arguments list the files to be included in the tar file.
1517 These files must all exist. Any files which don't exist or can't be
1518 read are silently ignored.
1520 If the archive creation fails for any reason, C<create_archive> will
1521 return false. Please use the C<error> method to find the cause of the
1524 Note that this method does not write C<on the fly> as it were; it
1525 still reads all the files into memory before writing out the archive.
1526 Consult the FAQ below if this is a problem.
1530 sub create_archive {
1533 my $file = shift; return unless defined $file;
1534 my $gzip = shift || 0;
1538 return $class->_error( qq[Cowardly refusing to create empty archive!] );
1541 my $tar = $class->new;
1542 $tar->add_files( @files );
1543 return $tar->write( $file, $gzip );
1546 =head2 Archive::Tar->iter( $filename, [ $compressed, {opt => $val} ] )
1548 Returns an iterator function that reads the tar file without loading
1549 it all in memory. Each time the function is called it will return the
1550 next file in the tarball. The files are returned as
1551 C<Archive::Tar::File> objects. The iterator function returns the
1552 empty list once it has exhausted the the files contained.
1554 The second argument can be a hash reference with options, which are
1555 identical to the arguments passed to C<read()>.
1559 my $next = Archive::Tar->iter( "example.tar.gz", 1, {filter => qr/\.pm$/} );
1561 while( my $f = $next->() ) {
1562 print $f->name, "\n";
1564 $f->extract or warn "Extraction failed";
1574 my $filename = shift or return;
1575 my $compressed = shift or 0;
1576 my $opts = shift || {};
1578 ### get a handle to read from.
1579 my $handle = $class->_get_handle(
1587 return shift(@data) if @data; # more than one file returned?
1588 return unless $handle; # handle exhausted?
1590 ### read data, should only return file
1591 @data = @{ $class->_read_tar($handle, { %$opts, limit => 1 }) };
1593 ### return one piece of data
1594 return shift(@data) if @data;
1596 ### data is exhausted, free the filehandle
1602 =head2 Archive::Tar->list_archive($file, $compressed, [\@properties])
1604 Returns a list of the names of all the files in the archive. The
1605 first argument can either be the name of the tar file to list or a
1606 reference to an open file handle (e.g. a GLOB reference).
1608 If C<list_archive()> is passed an array reference as its third
1609 argument it returns a list of hash references containing the requested
1610 properties of each file. The following list of properties is
1611 supported: full_path, name, size, mtime (last modified date), mode,
1612 uid, gid, linkname, uname, gname, devmajor, devminor, prefix.
1614 See C<Archive::Tar::File> for details about supported properties.
1616 Passing an array reference containing only one element, 'name', is
1617 special cased to return a list of names rather than a list of hash
1624 my $file = shift; return unless defined $file;
1625 my $gzip = shift || 0;
1627 my $tar = $class->new($file, $gzip);
1630 return $tar->list_files( @_ );
1633 =head2 Archive::Tar->extract_archive($file, $compressed)
1635 Extracts the contents of the tar file. The first argument can either
1636 be the name of the tar file to create or a reference to an open file
1637 handle (e.g. a GLOB reference). All relative paths in the tar file will
1638 be created underneath the current working directory.
1640 C<extract_archive> will return a list of files it extracted.
1641 If the archive extraction fails for any reason, C<extract_archive>
1642 will return false. Please use the C<error> method to find the cause
1647 sub extract_archive {
1649 my $file = shift; return unless defined $file;
1650 my $gzip = shift || 0;
1652 my $tar = $class->new( ) or return;
1654 return $tar->read( $file, $gzip, { extract => 1 } );
1657 =head2 $bool = Archive::Tar->has_io_string
1659 Returns true if we currently have C<IO::String> support loaded.
1661 Either C<IO::String> or C<perlio> support is needed to support writing
1662 stringified archives. Currently, C<perlio> is the preferred method, if
1665 See the C<GLOBAL VARIABLES> section to see how to change this preference.
1669 sub has_io_string { return $HAS_IO_STRING; }
1671 =head2 $bool = Archive::Tar->has_perlio
1673 Returns true if we currently have C<perlio> support loaded.
1675 This requires C<perl-5.8> or higher, compiled with C<perlio>
1677 Either C<IO::String> or C<perlio> support is needed to support writing
1678 stringified archives. Currently, C<perlio> is the preferred method, if
1681 See the C<GLOBAL VARIABLES> section to see how to change this preference.
1685 sub has_perlio { return $HAS_PERLIO; }
1687 =head2 $bool = Archive::Tar->has_zlib_support
1689 Returns true if C<Archive::Tar> can extract C<zlib> compressed archives
1693 sub has_zlib_support { return ZLIB }
1695 =head2 $bool = Archive::Tar->has_bzip2_support
1697 Returns true if C<Archive::Tar> can extract C<bzip2> compressed archives
1701 sub has_bzip2_support { return BZIP }
1703 =head2 Archive::Tar->can_handle_compressed_files
1705 A simple checking routine, which will return true if C<Archive::Tar>
1706 is able to uncompress compressed archives on the fly with C<IO::Zlib>
1707 and C<IO::Compress::Bzip2> or false if not both are installed.
1709 You can use this as a shortcut to determine whether C<Archive::Tar>
1710 will do what you think before passing compressed archives to its
1715 sub can_handle_compressed_files { return ZLIB && BZIP ? 1 : 0 }
1717 sub no_string_support {
1718 croak("You have to install IO::String to support writing archives to strings");
1725 =head1 GLOBAL VARIABLES
1727 =head2 $Archive::Tar::FOLLOW_SYMLINK
1729 Set this variable to C<1> to make C<Archive::Tar> effectively make a
1730 copy of the file when extracting. Default is C<0>, which
1731 means the symlink stays intact. Of course, you will have to pack the
1732 file linked to as well.
1734 This option is checked when you write out the tarfile using C<write>
1735 or C<create_archive>.
1737 This works just like C</bin/tar>'s C<-h> option.
1739 =head2 $Archive::Tar::CHOWN
1741 By default, C<Archive::Tar> will try to C<chown> your files if it is
1742 able to. In some cases, this may not be desired. In that case, set
1743 this variable to C<0> to disable C<chown>-ing, even if it were
1746 The default is C<1>.
1748 =head2 $Archive::Tar::CHMOD
1750 By default, C<Archive::Tar> will try to C<chmod> your files to
1751 whatever mode was specified for the particular file in the archive.
1752 In some cases, this may not be desired. In that case, set this
1753 variable to C<0> to disable C<chmod>-ing.
1755 The default is C<1>.
1757 =head2 $Archive::Tar::DO_NOT_USE_PREFIX
1759 By default, C<Archive::Tar> will try to put paths that are over
1760 100 characters in the C<prefix> field of your tar header, as
1761 defined per POSIX-standard. However, some (older) tar programs
1762 do not implement this spec. To retain compatibility with these older
1763 or non-POSIX compliant versions, you can set the C<$DO_NOT_USE_PREFIX>
1764 variable to a true value, and C<Archive::Tar> will use an alternate
1765 way of dealing with paths over 100 characters by using the
1766 C<GNU Extended Header> feature.
1768 Note that clients who do not support the C<GNU Extended Header>
1769 feature will not be able to read these archives. Such clients include
1770 tars on C<Solaris>, C<Irix> and C<AIX>.
1772 The default is C<0>.
1774 =head2 $Archive::Tar::DEBUG
1776 Set this variable to C<1> to always get the C<Carp::longmess> output
1777 of the warnings, instead of the regular C<carp>. This is the same
1778 message you would get by doing:
1784 =head2 $Archive::Tar::WARN
1786 Set this variable to C<0> if you do not want any warnings printed.
1787 Personally I recommend against doing this, but people asked for the
1788 option. Also, be advised that this is of course not threadsafe.
1792 =head2 $Archive::Tar::error
1794 Holds the last reported error. Kept for historical reasons, but its
1795 use is very much discouraged. Use the C<error()> method instead:
1797 warn $tar->error unless $tar->extract;
1799 =head2 $Archive::Tar::INSECURE_EXTRACT_MODE
1801 This variable indicates whether C<Archive::Tar> should allow
1802 files to be extracted outside their current working directory.
1804 Allowing this could have security implications, as a malicious
1805 tar archive could alter or replace any file the extracting user
1806 has permissions to. Therefor, the default is to not allow
1807 insecure extractions.
1809 If you trust the archive, or have other reasons to allow the
1810 archive to write files outside your current working directory,
1811 set this variable to C<true>.
1813 Note that this is a backwards incompatible change from version
1816 =head2 $Archive::Tar::HAS_PERLIO
1818 This variable holds a boolean indicating if we currently have
1819 C<perlio> support loaded. This will be enabled for any perl
1820 greater than C<5.8> compiled with C<perlio>.
1822 If you feel strongly about disabling it, set this variable to
1823 C<false>. Note that you will then need C<IO::String> installed
1824 to support writing stringified archives.
1826 Don't change this variable unless you B<really> know what you're
1829 =head2 $Archive::Tar::HAS_IO_STRING
1831 This variable holds a boolean indicating if we currently have
1832 C<IO::String> support loaded. This will be enabled for any perl
1833 that has a loadable C<IO::String> module.
1835 If you feel strongly about disabling it, set this variable to
1836 C<false>. Note that you will then need C<perlio> support from
1837 your perl to be able to write stringified archives.
1839 Don't change this variable unless you B<really> know what you're
1846 =item What's the minimum perl version required to run Archive::Tar?
1848 You will need perl version 5.005_03 or newer.
1850 =item Isn't Archive::Tar slow?
1852 Yes it is. It's pure perl, so it's a lot slower then your C</bin/tar>
1853 However, it's very portable. If speed is an issue, consider using
1854 C</bin/tar> instead.
1856 =item Isn't Archive::Tar heavier on memory than /bin/tar?
1858 Yes it is, see previous answer. Since C<Compress::Zlib> and therefore
1859 C<IO::Zlib> doesn't support C<seek> on their filehandles, there is little
1860 choice but to read the archive into memory.
1861 This is ok if you want to do in-memory manipulation of the archive.
1863 If you just want to extract, use the C<extract_archive> class method
1864 instead. It will optimize and write to disk immediately.
1866 Another option is to use the C<iter> class method to iterate over
1867 the files in the tarball without reading them all in memory at once.
1869 =item Can you lazy-load data instead?
1871 In some cases, yes. You can use the C<iter> class method to iterate
1872 over the files in the tarball without reading them all in memory at once.
1874 =item How much memory will an X kb tar file need?
1876 Probably more than X kb, since it will all be read into memory. If
1877 this is a problem, and you don't need to do in memory manipulation
1878 of the archive, consider using the C<iter> class method, or C</bin/tar>
1881 =item What do you do with unsupported filetypes in an archive?
1883 C<Unix> has a few filetypes that aren't supported on other platforms,
1884 like C<Win32>. If we encounter a C<hardlink> or C<symlink> we'll just
1885 try to make a copy of the original file, rather than throwing an error.
1887 This does require you to read the entire archive in to memory first,
1888 since otherwise we wouldn't know what data to fill the copy with.
1889 (This means that you cannot use the class methods, including C<iter>
1890 on archives that have incompatible filetypes and still expect things
1893 For other filetypes, like C<chardevs> and C<blockdevs> we'll warn that
1894 the extraction of this particular item didn't work.
1896 =item I'm using WinZip, or some other non-POSIX client, and files are not being extracted properly!
1898 By default, C<Archive::Tar> is in a completely POSIX-compatible
1899 mode, which uses the POSIX-specification of C<tar> to store files.
1900 For paths greather than 100 characters, this is done using the
1901 C<POSIX header prefix>. Non-POSIX-compatible clients may not support
1902 this part of the specification, and may only support the C<GNU Extended
1903 Header> functionality. To facilitate those clients, you can set the
1904 C<$Archive::Tar::DO_NOT_USE_PREFIX> variable to C<true>. See the
1905 C<GLOBAL VARIABLES> section for details on this variable.
1907 Note that GNU tar earlier than version 1.14 does not cope well with
1908 the C<POSIX header prefix>. If you use such a version, consider setting
1909 the C<$Archive::Tar::DO_NOT_USE_PREFIX> variable to C<true>.
1911 =item How do I extract only files that have property X from an archive?
1913 Sometimes, you might not wish to extract a complete archive, just
1914 the files that are relevant to you, based on some criteria.
1916 You can do this by filtering a list of C<Archive::Tar::File> objects
1917 based on your criteria. For example, to extract only files that have
1918 the string C<foo> in their title, you would use:
1921 grep { $_->full_path =~ /foo/ } $tar->get_files
1924 This way, you can filter on any attribute of the files in the archive.
1925 Consult the C<Archive::Tar::File> documentation on how to use these
1928 =item How do I access .tar.Z files?
1930 The C<Archive::Tar> module can optionally use C<Compress::Zlib> (via
1931 the C<IO::Zlib> module) to access tar files that have been compressed
1932 with C<gzip>. Unfortunately tar files compressed with the Unix C<compress>
1933 utility cannot be read by C<Compress::Zlib> and so cannot be directly
1934 accesses by C<Archive::Tar>.
1936 If the C<uncompress> or C<gunzip> programs are available, you can use
1937 one of these workarounds to read C<.tar.Z> files from C<Archive::Tar>
1939 Firstly with C<uncompress>
1943 open F, "uncompress -c $filename |";
1944 my $tar = Archive::Tar->new(*F);
1947 and this with C<gunzip>
1951 open F, "gunzip -c $filename |";
1952 my $tar = Archive::Tar->new(*F);
1955 Similarly, if the C<compress> program is available, you can use this to
1956 write a C<.tar.Z> file
1961 my $fh = new IO::File "| compress -c >$filename";
1962 my $tar = Archive::Tar->new();
1967 =item How do I handle Unicode strings?
1969 C<Archive::Tar> uses byte semantics for any files it reads from or writes
1970 to disk. This is not a problem if you only deal with files and never
1971 look at their content or work solely with byte strings. But if you use
1972 Unicode strings with character semantics, some additional steps need
1975 For example, if you add a Unicode string like
1978 $tar->add_data('file.txt', "Euro: \x{20AC}");
1980 then there will be a problem later when the tarfile gets written out
1981 to disk via C<$tar->write()>:
1983 Wide character in print at .../Archive/Tar.pm line 1014.
1985 The data was added as a Unicode string and when writing it out to disk,
1986 the C<:utf8> line discipline wasn't set by C<Archive::Tar>, so Perl
1987 tried to convert the string to ISO-8859 and failed. The written file
1988 now contains garbage.
1990 For this reason, Unicode strings need to be converted to UTF-8-encoded
1991 bytestrings before they are handed off to C<add_data()>:
1994 my $data = "Accented character: \x{20AC}";
1995 $data = encode('utf8', $data);
1997 $tar->add_data('file.txt', $data);
1999 A opposite problem occurs if you extract a UTF8-encoded file from a
2000 tarball. Using C<get_content()> on the C<Archive::Tar::File> object
2001 will return its content as a bytestring, not as a Unicode string.
2003 If you want it to be a Unicode string (because you want character
2004 semantics with operations like regular expression matching), you need
2005 to decode the UTF8-encoded content and have Perl convert it into
2009 my $data = $tar->get_content();
2011 # Make it a Unicode string
2012 $data = decode('utf8', $data);
2014 There is no easy way to provide this functionality in C<Archive::Tar>,
2015 because a tarball can contain many files, and each of which could be
2016 encoded in a different way.
2024 =item Check if passed in handles are open for read/write
2026 Currently I don't know of any portable pure perl way to do this.
2027 Suggestions welcome.
2029 =item Allow archives to be passed in as string
2031 Currently, we only allow opened filehandles or filenames, but
2032 not strings. The internals would need some reworking to facilitate
2033 stringified archives.
2035 =item Facilitate processing an opened filehandle of a compressed archive
2037 Currently, we only support this if the filehandle is an IO::Zlib object.
2038 Environments, like apache, will present you with an opened filehandle
2039 to an uploaded file, which might be a compressed archive.
2047 =item The GNU tar specification
2049 C<http://www.gnu.org/software/tar/manual/tar.html>
2051 =item The PAX format specication
2053 The specifcation which tar derives from; C< http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html>
2055 =item A comparison of GNU and POSIX tar standards; C<http://www.delorie.com/gnu/docs/tar/tar_114.html>
2057 =item GNU tar intends to switch to POSIX compatibility
2059 GNU Tar authors have expressed their intention to become completely
2060 POSIX-compatible; C<http://www.gnu.org/software/tar/manual/html_node/Formats.html>
2062 =item A Comparison between various tar implementations
2064 Lists known issues and incompatibilities; C<http://gd.tuwien.ac.at/utils/archivers/star/README.otherbugs>
2070 This module by Jos Boumans E<lt>kane@cpan.orgE<gt>.
2072 Please reports bugs to E<lt>bug-archive-tar@rt.cpan.orgE<gt>.
2074 =head1 ACKNOWLEDGEMENTS
2076 Thanks to Sean Burke, Chris Nandor, Chip Salzenberg, Tim Heaney, Gisle Aas
2077 and especially Andrew Savige for their help and suggestions.
2081 This module is copyright (c) 2002 - 2008 Jos Boumans
2082 E<lt>kane@cpan.orgE<gt>. All rights reserved.
2084 This library is free software; you may redistribute and/or modify
2085 it under the same terms as Perl itself.